password-protected area for uploads / downloads

The assignment is to create password-protected area of a web site for fictitious research organization ("think tank" of researchers) working on several projects. The members of the "think tank" are stuff researchers, research managers, guest researchers and administrators. The research is done by stuff researchers who upload the results of their research in the form of Excel spreadsheets and leave them in their individual research cubicles (to be implemented as file folders). Stuff researchers are organized into teams working on different projects. Each team of researchers is headed by one or more research managers. Research manager takes (i.e. downloads) their work from their cubicles and publishes the reports (i.e. upload Excel spreadsheets) in several newsrooms. These newsrooms are accessible during certain hours by select stuff researchers and managers as well as select guest researchers, who can only view (i.e. download) the reports. Theoretically the same person can be a member of 2 different teams, but, since his work for one team is not related to the other team, we shall treat him as 2 different members, sharing the same email and assign 2 different member ids. But that should not really happen. Features I need to have the usual set of features for this type of site such as login, logout, registration, lost password, edit member profile and change password, upload and download pages, error handling for unauthorized users going straight to specific url, admin page, etc. Code style and quality I am looking for experienced PHP developer to do this project. I expect secure, clean, modular, FULLY COMMENTED, professional quality code with the MEANINGFUL variable and function names. I must be able to understand every line of your code. I expect the developer to help me to understand the code by adding comments explaining what the code does. The site hosting still runs PHP 4.3, MySQL 4.1 and does not plan to upgrade. Since OOP in PHP 4 is limited and inefficient, please write mostly procedural code. ADODB for database abstraction would be fine, but if you plan to use any 3rd party libraries (including PEAR modules) please let me know before starting the project. Try to separate PHP code from the presentation HTML markup as much as possible. I do not need web design, presentation graphics, etc. I shall do it later myself. I need basic, unrefined templates to test the PHP script now and to make them fancy later, without worrying too much about embedded PHP code.